Dynamic Method of Determination of Octanol-Water Partition Coefficient of 2,4-Dihydroxythiobenzanilides in QSAR Studies

The dynamic method to determine the octanol-water partition coefficient of 2,4-dihydroxythiobenzanilides on the basis of the spectrophotometrical data was used. The spectrophotometric investigations of lipophilicity were based on the changes of absorbance in time as the result of permeation of analyte from the aqueous to the octanol phase. The interpretation of the data was based on the reference equation for the correlation of the experimental results and the calculated values obtained from the calibration process (log P,). The calculated log P values from three different approaches were used comparatively. The best correlation between the experimental log P values and those determined according to the Broto's method was found. The linear relationships between log P obtained in different ways and the logarithmically transformed 1/MIC values are presented. The strains of dermatophytes, moulds and yeasts were used as bioindicators. In comparison to the experimentally obtained log P-r the calculated log P values correlated better with bioactivity. Significantly higher correlation was found with the fungistatic activity determined on moulds and yeasts than on dermatophytes.